Sealed ball joint for electrodes



April 3, 1962 w A. PHILLIPS SEALED BALL JOINT FOR ELECTRODES Filed Nov.50, 1959 IN VENTOR WE PNE R A. PHILLIPS ATTORNEY tinned States Patent3,028,183 SEALED BALL JOINT OR ELECTRODES Werner A. Phillips, Chemawa,0reg., assignor t0 the United tates of America as represented by theSecretary of the Interior Filed Nov. 30, 1959, Ser. No. 856,317 3Claims. (Cl. 287-87) (Granted under Title 35, US. Code (1952), see. 266)The invention herein described and claimed may be manufactured and usedby or for the Government of the United States of America forgovernmental purposes without the payment of royalties therein ortherefor.

This invention relates to improved ball joints for rod or shaft membersextending through a Wall section, whereby the rods may be moved axiallyand from side to side on one side of the the wall by manipulating therod portion extending through on the other side. The

Y embodiment shown herein is adapted for providing a vacuum-tight jointfor water cooled electrodes in a vacuum are melting furnace. However,the device is not limited to this use but may be employed broadlywherever fluid tight ball joints or stufiing boxes are required.

Briefly, the improved ball joint device consists of a seating memberadapted to be fastened to a Wall or panel section of a vacuum chamber.The seating member'has a ground concave spherical inner bearing portionadapted to receive a ball member. Stuffing glands and packing permitrotation of the ball but maintain it in vacuumtight conditions. A shaftextends through a diametrical bore in the hall, said shaft having astufilng gland and packing to permit axial movement while retaining thevacuum.

In the arc furnaces used heretofore for the test melting of refractorymetals, a fixed electrode was provided which allowed-melting of only onetest button at a time. After melting, the furnace had to be disassembledto remove the button. By providing a vacuum-tight ball joint, the watercooled electrode may be moved to different stations within the furnacewithout disturbing the rest of the set-up so that a plurality of testbuttons may be formed before opening the furnace.

it is an object of this invention to provide an improved fluid orvacuum-tight ball joint for rods or shafts extending through a wallsection.

It is a further object of this invention to provide a novel improvedball joint having separate means for compressing a gasket surroundingthe ball, and for retaining the ball against its seat.

These and other objects of the invention will be more apparent onconsideration of the accompanying drawing and the following descriptionthereof.

FIG. 1 is a view partly in section of a portion of the vacuum electricfurnace, showing the water-cooled electrode passing through the balljoint.

FIG. 2 is an enlarged cross-sectional view of the ball joint andassociated electrode structure.

FIG. 3 is a view taken along lines 3-4 of FIG. 2.

Referring to FIG. 1, 1 is a double-walled shell of an electric furnace,with water flowing in the hollow portion for cooling purposes. Fastenedto the shell by bolts 2 is the ball joint assembly 3 having a ballmember 4. Water-cooled electrode 5 having an internal water inlet pipe 6and an external water outlet pipe 7, an electrical connection terminal8, and a tungsten tip 9, passes through ball 4.

As best shown in FIG. 2, ball 4 is seated in housing 10 which has alower spherical cup-shaped inner surface adapted to receive ball 4, andis fastened to the furnace shell by bolts 2, rings 11 and 12, andsleeves 13. Members 11, 12 and 13, which may be of any suitable insulat-"ice ing material, electrically insulate ball joint assembly 3 from therest of the furnace structure. 0 rings 15 and 16 fitted into associatedgrooves in shell 1 and ring 11 respectively, serve as vacuum-tight sealswhen compressed.

At the upper circumferential portion of'the spherical bearing surface ofhousing 10, a circumferential shoulder 17 is provided into which aresilient O ring or gasket 1-8 fits snugly. Upper portion 19 of housing10 is threaded internally, and stufilng gland 20, which is justtangential to, or free of contact with the ball, is threadably engagedtherewith, compressing 0 ring 18. Thereby the junction of ball 4 andhousing It) is made vacuum-tight. Gland 20 has inner threads whichengage corresponding threads on ball nut 21. By tightening pressure nut21 the ball may be held in any desired position.

The avoidance of any hold-down pressure on the ball due to stufiinggland 20' and the provision of a separate nut 21 to retain the ball arevery important features of this invention. In previous ball joints boththese functions were performed by a single gland member. This wasunsatisfactory because the amount of compression on the O ring 17 whichcould be achieved by tightening the ball. Separating the O ringcompression'and ball retention functionsby providing separate means foreach enables a more uniform and greater pressure on the 0 ring andtherefore a higher degree of vacuum to be achieved and maintained. pWater-cooled electrode 5 passes through a diametrical opening 22 in ball4, the upper end of which is enlarged to bore'23, a ledge '24 joiningbores 22 and 23. The

latter is internally threaded to receive a gland nut 25. An

nace in vacuum-tight condition.

Any conventional. material of construction suitable for the conditionsof service may be employed. Thus, the 0- ring may be made of anysuitable elastomer suchnas; noeprene, while the seats, ball and glandmembers. may be made of brass or steel.

It is obvious that the above described invention is susceptible of muchmodification and varied uses, and the scope thereof is limited only bythe following claims.

I claim:

l. A ball joint for a rod passing through an opening in a platecomprising, a seating member fastened to the late and mounted within theopening, said seating member having a spherical cup-shaped bearingsurface, including a central opening and an upper circumferentialshoulder, a spherical ball member seated on said cupshaped sphericalbearing surface, said ball member having an axial bore including anupper enlarged portion and a ledge at the bottom of the enlargedportion, whereby the rod may be slidably mounted in said ball memberthrough said axial bore, first resilient gasket means mounted in saidcircumferential shoulder adjacent to the ball member, an apertured firststuffing gland threadably connected to the seating member, said stuffinggland having at most tangential contact with the ball member within theaperture. and an integral portion thereof operably displa-ceable withinthe seating member to engage the first resilient gasket means andcompress it, an aperture'd nut member threadably connected with andlocated within the aperture of the first stufling gland, said nut memberhaving an integral portion thereof operable for engaging the ball memberand exerting a bearing pressure thereon, a second resilient gasket meansmounted on the ledge within the axial bore of the ball member, and asecond apertured stalling gland adapted to slidably fit over the rodthreadably mounted in the axial bore of said ball member, said secondstuffing gland land was limited by contact of the gland with the havingan integral portion thereof operably displaceable Within the ball memberto engage the second resilient gasket to compress it.

2. An improved ball joint sealing structure comprising a seating memberhaving a spherical cup-shaped bearing portion, said seating memberhaving an upper circumferential shoulder, a spherical ball member seatedin said cup-shaped bearing portion, resilient gasket means mounted insaid circumferential shoulder adjacent the ball member, hollowcylindrical stufling gland means comprising a bearing end face,interiorly a smooth cylindrical surface, an adjusting flange arrangedexteriorly on said gland means opposite to said bearing end, and anengageable surface adjacent said smooth surface and said exteriorflange, said stuffing gland being adjustably mounted in said seatingmember to apply the bearing end face thereof to engage the gasket tocompress it, the internal diameter of the stufling gland being at leastequal to the diameter of the ball member whereby the latter is at mostin tangential contact with the said smooth interior surface of thestuffing gland, permitting facile relative movement between the ballmember and said smooth surface at any degree of adjustment of thestufling gland with the seating member to compress the gasket, and anadjustable pressure means comprising as parts at opposite ends thereof,a bearing surface portion, and an adjusting flange respectively, and anintermediate portion thcrebetween having interengaging means operableupon the said interior engageable surface of the stufiing gland, wherebysaid bearing surface portion is displaced relative to the stufiing glandupon adjustment of said flange part and is thereby made operable tocontact the ball member above said gasket to force the ball memberagainst the seating member independently of the degree of adjustment ofthe stufling gland and the pressure applied thereby uPQn the gasket, andwherein one of said adjusting flanges extends out from within the otherto facilitate the said independent adjustment.

3. An improved ball joint sealing structure comprising a seating memberhaving a'spherical cup-shaped bearing portion, said seating memberhaving an upper circumferential shoulder, a spherical ball member seatedin said a 4 cup-shaped bearing portion, resilient gasket means mountedin said circumferential shoulder adjacent the ball member, hollowcylindrical stufling gland means comprising a bearing end face, aninterior smooth cylindrical surface, an adjusting flange arrangedexteriorly on said gland means opposite to said bearing end, and anengageable surface adjacent said smooth surface and said exteriorflange, said stufiing gland being adjusta-bly mounted in said seatingmember by means of cooperatively engaging threads in said seating memberand on said stufling gland, to apply the bearing end thereof to engagethe gasket to compress it, the internal diameter of the stufling glandbeing at least equal to the diameter of the ball member whereby thelatter is at most in tangential contact with the said smooth interiorsurface of the stuffing gland, permitting facile relative movementbetween the ball member and said smooth surface at any degree ofadjustment of the stufling gland with the seating member to compress thegasket, and an adjustable pressure means comprising a nut means havingas integral parts at opposite ends thereof, a bearing surface means, andan adjusting flange, respectively, and an intermediate portiontherebetween threadably connected and operable upon the said interiorengageable surface of the stuffing gland, whereby said bearing surfacemeans is made operable upon adjustment of said flange part to contactthe ball member above said gasket, and exert a bearing pressure thereonto force the ball member against the seating member independently of thedegree of adjustment of the stufling gland and the pressure appliedthereby upon the gasket, and wherein one of said adjusting flangesextends out from within the other to facilitate the said independentadjustment.

References Cited in the file of this patent UNITED STATES PATENTS343,769 Levi June 15, 1886 409,277 Curley Aug. 20, 1889 900,603 SilkOct. 6, 1908 908,414 Mellin Dec. 29, 19-98 909,263 Walters Jan. 12, 19091,752,696 Roberts et al. Apr. 1, 1930

